(1) Field of the Invention
The present invention relates to an air conditioner capable of distributing the temperature in a room uniformly regardless of the installation position of an indoor unit of the air conditioner.
(2) Description of Prior Art
FIG. 10 is a diagram showing an electric circuit for setting the rotation speed of an indoor fan in the indoor unit of a conventional air conditioner, which was disclosed in Published Unexamined Japanese patent application No. 28152/1977. In FIG. 10, reference numeral 1 designates an AC power source; 2, a blowing power switch for changing the rotation speed of a motor 3 for driving the indoor fan to one of "HIGH", "LOW" and "GENTLE" for instance; and 4, a start capacitor.
With such an electric circuit as shown in FIG. 10, the rotational speed of the indoor fan is varied according by switching the blowing power switch 2. Assuming that the direction of air blow produced by the indoor fan is directed downwardly during a heating operation for instance, the air blow stream from the indoor unit 5 in is room 6 is as shown in FIG. 11. As the rotation speed of the fan increases, the heated air flow stream varies as indicated by "a", "b" and "c" in FIG. 11, respectively. More specifically, in the case where the blowing power switch 2 selects the "HIGH" air blow power operation, the temperature of the heated air blow blown downwardly becomes relatively low and the flow path thereof is relatively long. As a result, as indicated by the "c" in FIG. 11, air in the room can be agitated well resulting in uniform room temperature distribution. In this case, however, the "HIGH" air blow may be uncomfortable to people in the room and further the indoor fan is noisy when rotating at a high speed. Consequently, while the above described good agitation effect can be obtained by the "HIGH" air blow power operation, in view of the shortcomings, there is a tendency to use the air conditioner under the "LOW" or "GENTLE" air blow power operation.
In the "LOW" or "GENTLE" air blow power operation, the flow path of the heated air blown downwardly is shortened as indicated by the "a" or "b" in FIG. 11. Further, as shown in FIG. 12, in case where the installation position (height) d from a floor 8 of the room is relatively high, it is disadvantageous in that the heated air blow may be directed upwardly before reaching the floor 8. This results in degrading the room temperature distribution.
Moreover, in the case where the installation position of the indoor unit 5 to a wall 9 of the room is one onesided, as shown in FIG. 13, it is unlikely that the heated air blow will expand horizontally near to the floor 8. In addition, it is also disadvantageous in that it may be difficult for the heated air blow to reach the center of the room or another side of the room opposite to the installation position. This results in degrading performance of the air conditioner such as making the room temperature distribution non uniform.
The conventional air conditioner thus constructed has drawbacks that uniform room temperature distribution may not be always obtained depending on the installation conditions, particularly the installation height from a floor and the installation position in a horizontal direction with respect to a center of a wall, in case of selecting the lower rotation speed of the fan, (i.e., the "LOW" or "GENTLE" air flow power operation) that is used frequently during not only the heating operation but also the cooling or circulating operation. In other words, with the thus constructed prior art air conditioner, there may be a problem that the heated or cooled air blow may not arrive at the floor thereby resulting in degrading the room temperature distribution during the relatively lower rotation speed operation of the fan.